1. Field of the Invention
The invention relates to self-retaining bolt assemblies; and, more particularly, to an adjustable diameter bolt assembly for use in aircraft and other similar installations.
2. Description of the Prior Art
Self-retaining bolts are well known in the aircraft industry. Such bolts are mounted in one panel and adapted to be selectively coupled to and disengaged from a mating member mounted in an adjacent panel. Such prior art bolts include means thereon for retaining the bolt to the panel in which it is installed so that it can't fall out during vibration or the like even if it is not connected to its mating member and for allowing subsequent easy release therefrom. One type of prior art bolt is disclosed in U.S. Pat. No. 4,759,671. In this patent, a self-retaining bolt is disclosed having means for retaining the bolt to the panel in which it is installed without weakening the bolt while permitting easy release therefrom. Such means is easy to manufacture and install, require relatively few working parts and does not require orientation in a fixed direction for assembly.
However, the holes in the panels in which such bolts are installed vary in internal diameter. It is difficult to provide a bolt having a shank diameter that tightly fits in all such panel holes. There is thus a need for filling the spacing between the bolt shank and the hole walls of the panel in which the bolt is installed. Bushing segments are known which are used to fill such spacing, such as those disclosed in U.S. Pat. No. 3,192,820 to Pitzer. In U.S. Pat. No. 3,192,820 to Pitzer, there is disclosed a quick release pin having a plurality of male and female rings or bushings which, when compressed axially as a result of a compressive force applied to one end of the bushings, forces the male rings to contract and the female rings to expand to assume a larger diameter. That is, the effective diameter of the quick release pin can be increased after the pin is installed in a hole or opening in an installation. In like manner, the effective diameter of the pin can be reduced (or returned to its original diameter) when it is desired to remove the pin from the installation. There is a need for applying such bushing segments to a self-retaining bolt, as disclosed in U.S. Pat. No. 4,759,671, while protecting the pawl during the torquing of the bushing segments.